1. Field of the Invention
The present invention generally relates to a recording condition setting method, program, recording medium, and information recording apparatus. More particularly, the present invention relates to a recording condition setting method for setting a recording condition when recording information to an information recording apparatus, a program used for a recording apparatus, a recording medium having the program recorded thereto, and a recording apparatus for recording information to a recording medium.
2. Description of the Related Art
Due to improvements made in the functions of personal computers in recent years, the personal computer has become able to handle audio-visual information such as music and images. Since audio-visual information contains a vast amount of data, optical disks such as CDs (Compact Disc), and DVDs (Digital Versatile Disc) have gained attention for use as information recording media. Furthermore, as the costs for such optical disks become lower, an optical disk apparatus has become widely employed as a personal computer peripheral serving as an information recording apparatus. The optical disk apparatus records and erases information by irradiating a fine spot of laser light to spiral or concentric tracks formed on a recording surface of an optical disk, and reproduces information according to the light reflected from the recording surface. The optical disk apparatus has an optical pickup unit arranged thereto for irradiating the laser light to the recording surface of the optical disk and also for receiving the light reflected from the recording surface.
Typically, the optical pickup unit includes, for example, a light source for irradiating a laser light of a prescribed irradiation power (output power), an optics system for guiding the laser light irradiated from the light source to a recording surface of an information recording medium and also for guiding the laser light reflected from the recording surface to a prescribed light receiving location, and a light receiving element positioned at the light receiving location.
Information is recorded in the optical disk according to the lengths and combination of marked areas (pits) and unmarked areas (space), which have different reflectivities. In recording the information in the optical disk, the irradiation power of the light source is controlled so that the marked areas and space areas may be formed at a prescribed location and thus with a prescribed length.
In a case of forming marked areas in a recordable type optical disk (hereinafter referred to as “dye type disk”) which contains organic dye in a recording layer thereof, (e.g. CD-R (CD-recordable) disk, DVD-R (DVD-recordable) disk), a laser light with an increased irradiation power is applied to the dye type disk to heat and melt the dye, thereby transmuting or transforming a substrate portion contacting the area at which the laser light is applied. Meanwhile, in a case of forming space areas, the irradiation power of the laser light is reduced to a degree substantially equal to that during reproduction in order to prevent the substrate from transmuting and transforming. Therefore, the reflectivity of the marked areas is lower than that of the space areas.
Typically, the dye type disk exhibit significant changes in recording sensitivity in correspondence to changes in the wavelength of laser light. Therefore, changes in the wavelength of laser light will also change the optimum irradiation power when forming the marked areas (hereinafter referred to as “recording power”). Furthermore, changes in the temperature of the light source will change the wavelength of the laser light irradiated from the light source. That is, the optimum recording power will change in correspondence to a change in the temperature of the light source.
Accordingly, Japanese Laid-Open Patent Publication No. 2001-297437(hereinafter referred to as “first conventional example”), for example, shows an optical recording apparatus having a temperature sensor disposed near an optical pickup unit, in which the temperature near the optical pickup unit is detected by the temperature sensor during a recording process. When the temperature surpasses a prescribed value, the optical recording apparatus performs a test-recording procedure for obtaining an optimum recording power, so-called OPC (Optimum Power Control) procedure.
In another example, Japanese Laid-Open Patent Publication No. 5-144061. (hereinafter referred to as “second conventional example”) shows an irradiation power control apparatus in which the apparatus obtains the optimum recording power of a laser beam irradiated from a laser diode in accordance with an identification code of an optical disk, relates the temperature near the laser diode in correspondence to the obtained optimum recording power of the identification code, stores the temperature information in a memory, and controls the irradiation power of the laser diode according to the temperature information. The irradiation power control apparatus reads the identification code of the optical disk prior to recording in the optical disk, derives the temperature information corresponding to the identification code from the memory, and performs the OPC procedure when the difference in the value between the derived temperature and the temperature detected from a sensor disposed near the laser diode surpasses a prescribed value, to thereby obtain the optimum recording power.
In another example, Japanese Patent Laid-Open Publication No. 6-76288(hereinafter referred to as “third conventional example”) shows an optical disk apparatus in which the optical disk apparatus performs a running OPC procedure to enable correction of recording power. The optical disk apparatus first performs a standard OPC procedure to obtain the optimum recording power, and begins recording in accordance with the obtained optimum recording power. Subsequently, upon forming pits in an optical disk, the optical disk apparatus detects the intensity of the light reflected from the recording area and corrects the recording power based on the difference between a predetermined value and the value of the detected intensity.
Recordable type optical disks are formed with a test-recording area for determining optimum recording power. This area is called a “power calibration area (PCA)”. For example, a CD-R has a PCA serving as a test-recording area divided into 100 partitions. Each of the partitions of the test-recording area is formed of 15 frames. Typically, a single partition is used for test-recording prescribed data in an optical disk where the test-recording is performed with a certain linear speed and where recording power for each frame is changed step by step. Accordingly, among the recording power level for each of the frames, the recording power displaying the highest recording quality is chosen as the optimum recording power. Nevertheless, since the optical recording apparatus of the first conventional example and the irradiation power control apparatus of the second conventional example both perform the OPC procedure whenever a value corresponding to temperature surpasses a prescribed value, both of the examples tend to face a problem of lacking the recording area sufficient for required test-recording. Furthermore, since the optical recording apparatus of the third conventional example always performs the OPC procedure prior to a recording procedure, the third example will also face the lack of sufficient test-recording area after repetitively recording small amounts of data.